Contaminants in an Over-the-Counter Medication and Their Effect on Rheumatoid Arthritis Diagnosis: A Case Report.

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Early diagnosis and intervention are critical, and contaminated medications can complicate or obscure the diagnosis of autoimmune diseases. Herein, we report a case of a 38-year-old man who presented with two to three months of worsening arthralgias and myalgias. He reported using AK Forte, a natural supplement from Mexico that was recalled by the FDA for contamination with diclofenac, dexamethasone, and methocarbamol. AK Forte is a popular supplement used in Latin America, especially amongst manual laborers and other physically demanding job workers, and is easily accessible over the counter. The patient also reported Cushingoid symptoms such as weight gain, facial puffiness, and stretch marks. Upon abruptly discontinuing AK Forte, the patient presented to the emergency department with worsening arthralgias, myalgias, intermittent fever, and tachycardia. Despite being on a supplement contaminated with steroids, the patient did not present with symptoms of adrenal insufficiency throughout his hospital course. After ruling out infectious causes, the patient was diagnosed with persistent sinus tachycardia associated with high RA inflammatory activity. This case demonstrates the importance of obtaining a thorough medication history, including over-the-counter drugs, vitamins, and herbal supplements. This case also highlights the risks associated with unregulated supplements, especially those sold outside the United States, as they may not adhere to FDA standards and may be contaminated with pharmacologically active ingredients, affecting their safety, efficacy, and quality.